扩展为在括号中包含负数：

In [1]: import locale, string

In [2]: from decimal import Decimal

In [3]: n = ['$1,234.56','-$1,234.56','($1,234.56)', '$ -1,234.56']

In [4]: tbl = string.maketrans('(','-')

In [5]: %timeit -n10000 [locale.atof( x.translate(tbl, '$)')) for x in n]

10000 loops, best of 3: 31.9 æs per loop

In [6]: %timeit -n10000 [Decimal( x.translate(tbl, '$,)')) for x in n]

10000 loops, best of 3: 21 æs per loop

In [7]: %timeit -n10000 [float( x.replace('(','-').translate(None, '$,)')) for x in n]

10000 loops, best of 3: 3.49 æs per loop

In [8]: %timeit -n10000 [float( x.translate(tbl, '$,)')) for x in n]

10000 loops, best of 3: 2.19 æs per loop

请注意，必须从float()/ Decimal()中去除逗号。带转换表的replace()或translate()均可用于将开头转换为(--，转换速度稍快。float()的速度最快为10-15倍，但缺乏精度，并且可能会出现语言环境问题。Decimal( )具有精度，比locale.atof()快50％，但也有语言环境问题，locale.atof()是最慢的，但最通用。

编辑：新的str.translateAPI(映射的字符None从str.translate函数移到转换表)

In [1]: import locale, string

from decimal import Decimal

locale.setlocale(locale.LC_ALL, '')

n = ['$1,234.56','-$1,234.56','($1,234.56)', '$ -1,234.56']

In [2]: tbl = str.maketrans('(', '-', '$)')

%timeit -n10000 [locale.atof( x.translate(tbl)) for x in n]

18 µs ± 296 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)

In [3]: tbl2 = str.maketrans('(', '-', '$,)')

%timeit -n10000 [Decimal( x.translate(tbl2)) for x in n]

3.77 µs ± 50.8 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)

In [4]: %timeit -n10000 [float( x.translate(tbl2)) for x in n]

3.13 µs ± 66.3 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)

In [5]: tbl3 = str.maketrans('', '', '$,)')

%timeit -n10000 [float( x.replace('(','-').translate(tbl3)) for x in n]

3.51 µs ± 84.8 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)